Fixes Zoom Normalization to properly scale by zoom ratio. If zooming in makes everything 3.4x larger on-screen, sensitivity will scale by a factor of 3.4x. Vanilla Zoom Normalization doesn't do this properly.
More technical explanation below:
By default the aim sensitivity setting makes sensitivity scale by adsFOV/hipFOV. This mod changes it to adsFocalLength/hipFocalLength.
This is important because then sensitivity properly scales by the zoom. Make sure you have FOV Relative Sensitivity checked in-game, and probably have "separate sensitivity" unchecked unless you know what you're doing. An example from in-game:
When aiming I zoomed in by about 1.5 times, shown by the center image being shrunk by 1.5x and overlaid. The mod makes sensitivity scale using the same math.